Flattening chisel backs with waterstones

[Dan McGonigle]

Hey guys, ive decided I need to get more serious about my sharpening. The 10 or 12 chisels and 7 or 8 hand planes I use were all sharpened and set up before I really knew much about sharpening. Until now I've been using 1000 and 6000 grit Japanese style waterstones, keeping the 1000 flat with sandpaper on granite and flattening the 6000 with the 1000. Recently I bought an 8000 stone and a leather strop and 1 micron compound. I'm going back through all my edge tools and re-flattening, setting new bevels and re-honing. I've started by flattening chisel backs on a 220 stone, keeping the stone flat with loose silicone carbide on granite. Working on the 220 stone I'm getting immediate results. Marking the back with a sharpie, only after a few strokes the marks are gone and I get a uniform scratch pattern. Moving on to the 1000, things are going slow. I'm not getting a uniform scratch pattern after a few minutes of working back and forth and it appears I have a low spot or two that the 1000 isn't touching. I'm taking care to not dish the stone and re-flattening it frequently. Am I making a mistake going from 220 - 1000? Or should I lower my time expectations and keep working on the 1000 until I get the sheen I want to move on? The chisels are Narex brand, not super high quality but I've heard should get flat prettt quick.

[David Eisenhauer]

I would add in a step or two between 220 and 1,000. if nothing else, it will speed things up quite a bit. If I have a chisel back or plane iron that is really, really bad out of flat, I use 80#, 120#, 180#, 220 grit (or close to those grits) sand papers on glass, then go to both sides of a 300#/600# diamond plate, followed by an 800# King waterstone. After that, I go to my three daily use Sigma waterstones - 1,000#, 6,000 and 13,000#. If the chisel or plane iron is not as bad as that, I may start with the diamond plate, go to the 800# and then my three daily use stones. Basically, I pick a grit and try it out briefly for a quick assessment. If it looks to be not removing much of the hump or belly, then I drop down a few grits until I get to one that it appears to be doing some immediate good. I have found that it is quicker overall to start rough and work up rather than work, work, work with lighter grits.

[steven c newman]

I flatten on the side of the grinders wheel. simple, quick. then it can go through the other steps like the bevel.

[William Fretwell]

I've gone through this with a large Narex set. Many years later my son still comments "remember those chisels you flattened" with a big grin on his face. I wish he could remember a few other things!

So yes it's slow, use a series of stones and diamond plates if you have them. I flattened almost the whole back but recommend you don't!

Worth it? Having bought them what choice do you have? They are decent chisels but not my best.

[Robert Hazelwood]

What kind of stone is the 220? If its a waterstone then you need to be vigilant about flattening- course waterstones especially will go out of flat very quickly. Likely you'd need to re-flatten the stone many times during the course of flattening a chisel back, if you want to keep it really dead on. That's kind of a hassle, and is why I don't care for coarse waterstones for back flattening.

Anyways, if the 220 is going a bit out of flat as you're working with it, then that explains why you have low areas that the 1000 grit stone won't touch. The other thing is that the slurry/mud from a coarse stone seems to be able to put a scratch pattern on low areas, making it difficult to identify those low spots until you move to a finer stone. If you're going to use waterstones for this then it would be nice to have a stone between the 220 and 1000.

Personally I think it's hard to beat sandpaper for this job. 80 grit PSA on a decently large flat surface makes quick and accurate work- faster than any other method I've used, by far. Then you can use an intermediate grit before going to the 1000 grit waterstone.

[Hasin Haroon]

Dan, it sounds like your chisels were fettled (to a lower degree) before you bought your new stone and strop. If you are just enhancing the sharpness of your tools, likely the backs of the chisels aren't too far out of flat to begin with, so I would just skip the #220 and start at around #600. If your chisels are pretty decently flat you could just go to the #1000 directly to see how it fares. As others have mentioned, the jump between #220 and #1000 is pretty large, and #220 is a pretty coarse grit to use on a tool unless you need to reshape the edge.

[Robert Engel]

Scratches have to be removed incrementally 220 -> 1000 is to big a jump.

Go to 400, then 800 (or straight to 800), then 1000, then 4000, then 8000 then the strop and you'll have a nice mirror finish.

[Patrick Chase]

I've gone through this with a large Narex set. Many years later my son still comments "remember those chisels you flattened" with a big grin on his face. I wish he could remember a few other things!


I think I've said this in a couple other places, but the reason Narex chisels are inexpensive is because they use a hardening process (austempering) that produces relatively little distortion, and they therefore do all of their machining in the unhardened state. Post-HT machining is expensive.

The problem is that "relatively little distortion" is not "no distortion". Every set of Narex chisels that's ever passed through my hands has had at least one bellied chisel, and those can be an epic pain to fix. Platter grinders with diamond disks are the fastest option I've found, FWIW.

To the OP: If you can access it then you might want to check out David Charlesworth's FWW article (http://www.finewoodworking.com/2004/04/01/a-users-guide-to-waterstones) on the topic. The technique that he describes does a good job of maximizing the amount of tool flattening that you can accomplish between waterstone flattenings.

[Jim Koepke]

My experience with waterstones below 1000 led me to using sandpaper on tile or granite for the coarser grits. From 360 sandpaper to a 1000 grit water stone isn't a big jump.

The metal piles up on the sandpaper and needs to be removed often. A brush, vacuum or a strong magnet wrapped in paper does the trick.

jtk

[David Ragan]

I'm in the 'dont' skip grits camp.

Be not discouraged. It is surprising how fast and easy it is to work through the grits once you have a system.

When occasionally confronted w (given the opportunity?) the situation of having to remove a lot of metal, I tired of grinding the dickens out of my water stones, w all the truing/flattening of them during the process.

More metal needed to go, easier. I had no idea how to proceed, just needed something coarser, that did not need flattening (at the time was oblivious to diamond paste).

So, I printed some charts:

367322367321367323

Recall that you want a larger particle size (more coarse) for more removal of metal (we are at the very edge of my brain on this, so the engineers can go into the different alloys and appropriate abrasives.)

My coarsest DMT diamond is about 60um, and was too much work. So, from the above charts, I got out my Klingspor catalog, and started w FEPA (European grading system) 80-which is about a 200um size particle.

The picture below is what I wound up with-SiC self adhesive rolls. (I only use this system for times when a lot needs to be removed.)

Plate glass, 3/8"" thick for the 8 grades mounted on a flat shelf...the great jig on it's side behind the board is from VSC tools (somehow, I ground down my LV jig's brass roller on these super coarse surfaces:eek:, that's not supposed to happen, right?)

367320

The diagonal plate on top w 3 grades of abrasive is strictly for your issue-flattening backs; requires a different approach-no jig needed. (The glass there is just cut off scrap my Hardware store guy gives me.)

Sandpaper has it's detractors, However, sometimes I would rather just flatten/bevel/straighten, etc whatever it is in the shortest period of time, cost becomes less of a factor.

If the above plate glass is not flat enough given modern tolerances, I have not been able to tell it when switching over to the waterstones @ end of process.

Jim is correct about the swarf-it does accumulate rapidly (I have not tried magnets-great idea Jim)

[Mark Stutz]

I gave up on waterstones for flattening chisels or plane irons very quickly. I almost obliterated the 220 half of a Norton stone in a very short time.

[Patrick Chase]

I gave up on waterstones for flattening chisels or plane irons very quickly. I almost obliterated the 220 half of a Norton stone in a very short time.

Yeah, that is one extremely soft stone, and not worth the hassle IMO.

In other posts I've argued the "layer model of waterstone life", i.e. the stones contain a certain number of usable layers of abrasive, and you can roughly compare them to other media on that basis. 220# is about 60 um, so the 25 mm thick, $30 Norton 220 contains about 400 layers of abrasive (maybe a bit more because of the way the grains pack in, maybe a bit less because of the volume taken up by binder).

You're therefore paying about $0.08 per 3" x 8" layer of abrasive, or $0.30 per 9 x 11 sheet equivalent, which is not all that much cheaper than comparable quality Al-Oxide sandpaper. What this serves to demonstrate is that waterstones cease to have compelling economics at such coarse grits, and are therefore not worth the hassle.

[Rob Luter]

I use diamond plates for the coarser work, followed by 3M abrasive films stuck to thick glass mounted on MDF blocks. It's worked well for the last 10 years or so. I can get a mirror polish without a whole bunch of effort. In the grand scheme of things, it was a cheap solution too.

https://c2.staticflickr.com/2/1488/26712452175_7e480b7af1_b.jpg

[Patrick Chase]

I use diamond plates for the coarser work, followed by 3M abrasive films stuck to thick glass mounted on MDF blocks. It's worked well for the last 10 years or so. I can get a mirror polish without a whole bunch of effort. In the grand scheme of things, it was a cheap solution too.

That looks simple but effective. Nice!

You appear to be using 1 um (green) and 0.3 um (white) 3M 261X film. Are you using an extra-extra-fine DMT plate (3 um abrasive) or something like that before the films? How long do the films last for you?

I use that stuff stuck to sticks a fair amount for tools with curved edges.

[David Ragan]

In other posts I've argued the "layer model of waterstone life", i.e. the stones contain a certain number of usable layers of abrasive, and you can roughly compare them to other media on that basis. 220# is about 60 um, so the 25 mm thick, $30 Norton 220 contains about 400 layers of abrasive (maybe a bit more because of the way the grains pack in, maybe a bit less because of the volume taken up by binder).

You're therefore paying about $0.08 per 3" x 8" layer of abrasive, or $0.30 per 9 x 11 sheet equivalent, which is not all that much cheaper than comparable quality Al-Oxide sandpaper. What this serves to demonstrate is that waterstones cease to have compelling economics at such coarse grits, and are therefore not worth the hassle.

Great analysis Patrick....the premise here is that one flattens often, and just until the pencil marks are gone?

I just had the feeling that for hogging off a lot of metal, sandpaper on stable substrate is the way to go.

Has anyone ever done an empirical test to see if your calculations translate into real world comparable results? Anybody have a diligent teenager that we could take up a collection and do a trial?

[Pat Barry]

Yeah, that is one extremely soft stone, and not worth the hassle IMO.

In other posts I've argued the "layer model of waterstone life", i.e. the stones contain a certain number of usable layers of abrasive, and you can roughly compare them to other media on that basis. 220# is about 60 um, so the 25 mm thick, $30 Norton 220 contains about 400 layers of abrasive (maybe a bit more because of the way the grains pack in, maybe a bit less because of the volume taken up by binder).

You're therefore paying about $0.08 per 3" x 8" layer of abrasive, or $0.30 per 9 x 11 sheet equivalent, which is not all that much cheaper than comparable quality Al-Oxide sandpaper. What this serves to demonstrate is that waterstones cease to have compelling economics at such coarse grits, and are therefore not worth the hassle.
Cost is probably at least double what you have outlined. Two reasons: 1) you need to periodically flatten that stone and that wastes away abrasive; and 2) you can't use the entire thickness - there must be some lower limit, what, maybe 1/3 to 1/4 of the original thickness?

Have you done similar calculations for the finer grit waterstones?

[Brian Holcombe]

Thin stones can be glued to a piece of float glass and continued to be used until they're basically gone.

[Patrick Chase]

Cost is probably at least double what you have outlined. Two reasons: 1) you need to periodically flatten that stone and that wastes away abrasive; and 2) you can't use the entire thickness - there must be some lower limit, what, maybe 1/3 to 1/4 of the original thickness?

w.r.t. flattening waste, that depends entirely on the user. Some people are so good at distributing the work that they barely ever flatten. Others flush basically the entire stone down the drain. Note that sandpaper has exactly the same issue, with uneven use leading to early demise.

w.r.t. lower thickness limits, most people deal with that by either gluing the stone to a holder (in which case you can basically use all of it) or cutting it up to make slips. Either way you do get full use of that remaining abrasive.


Have you done similar calculations for the finer grit waterstones?

Yep, in other threads. The short version is that stones have extremely favorable economics at grits higher than 1000# or so. A 10000# polisher has something like 25000 layers of abrasive. You can almost convince yourself that a Chosera 10K is a bargain if you torture the numbers enough (and don't include a Sigma 13K or any of the Imanishi polishers in your analysis).

[Patrick Chase]

Great analysis Patrick....the premise here is that one flattens often, and just until the pencil marks are gone?

Now we're getting into why I said it's a "rough" comparison.

Abrasives wear out, and need to be replaced when they do. With sandpaper you simply grab a new sheet. With a waterstone you do one of two things:

1. Pick a stone with binder hardness "matched" to the steels you hone, such that the stone releases abrasive grains right about when they're worn out.

2. Periodically reflatten the stone to expose fresh grain.

As an example of where the analysis becomes really rough, consider a very soft stone like a Sigma Select II 1000. That stone is designed to be used with HSS tools, so the binder is very soft and the abrasive (SiC) is itself prone to breaking down. If you use it on, say, HCS then it will shed abrasive long before the abrasive wears out, and you'll basically be flushing money down your sink,

[Pat Barry]

w.r.t. lower thickness limits, most people deal with that by either gluing the stone to a holder (in which case you can basically use all of it) or cutting it up to make slips. Either way you do get full use of that remaining abrasive.
I was thinking that waterstones would be porous and therefore would be susceptible to glue wicking up into the stone and creating other problems.

[David Ragan]

Now we're getting into why I said it's a "rough" comparison.

Abrasives wear out, and need to be replaced when they do. With sandpaper you simply grab a new sheet. With a waterstone you do one of two things:

1. Pick a stone with binder hardness "matched" to the steels you hone, such that the stone releases abrasive grains right about when they're worn out.

2. Periodically reflatten the stone to expose fresh grain.

As an example of where the analysis becomes really rough, consider a very soft stone like a Sigma Select II 1000. That stone is designed to be used with HSS tools, so the binder is very soft and the abrasive is itself (SiC) is prone to breaking down. If you use it on, say, HCS then it will shed abrasive long before the abrasive wears out, and you'll basically be flushing money down your sink,

Who knew?

I didn't.

Is there a central source for this oft-underappreciated information (i.e. discerning hardness/friability of stone w type of steel to be sharpened)?

[Rob Luter]

That looks simple but effective. Nice!

You appear to be using 1 um (green) and 0.3 um (white) 3M 261X film. Are you using an extra-extra-fine DMT plate (3 um abrasive) or something like that before the films? How long do the films last for you?

I use that stuff stuck to sticks a fair amount for tools with curved edges.

I just use a Smiths coarse and a DMT fine diamond stone to start. That will usually take care of any heavy lifting. I switch to the film after the backs are flat, rotating through all the grits in order to get a mirror polish. On plane irons I use the "ruler trick" with the two finest films. I use a Veritas guide to keep all the angles consistent when sharpening the bevel side. I wind up having to change the film a couple times a year, but I'm a hobbyist as opposed to a production woodworker.

[Patrick Chase]

I was thinking that waterstones would be porous and therefore would be susceptible to glue wicking up into the stone and creating other problems.

We use glues with high enough viscosity that they can't be pushed (much less wick) through the waterstone's pores. Also, you would want to make sure that the stone is very thoroughly dried before using anything that can be thinned by water, because the last thing you want to do is lower the glue's viscosity. Epoxy seems to be the most popular choice.

Without going into the fluid mechanics, an opening that just barely passes liquid water would be an effectively impermeable barrier (very high threshold pressure differential for migration) to any sort of gel-like glue.

[Rob Luter]

We use glues with high enough viscosity that they can't be pushed (much less wick) through the waterstone's pores. Also, you would want to make sure that the stone is very thoroughly dried before using anything that can be thinned by water, because the last thing you want to do is lower the glue's viscosity. Epoxy seems to be the most popular choice.

Without going into the fluid mechanics, an opening that just barely passes liquid water would be an effectively impermeable barrier (very high threshold pressure differential for migration) to any sort of gel-like glue.

I'm guessing that molten wax would work well too. Plenty of resistance to shear to keep the stone anchored. Easy to get it to release if you want as well. Just warm it up.

[Dan McGonigle]

Wow! A lot of useful info here, some of which went way over my head. So thanks everyone. Took me a few days to get out into the shop but I finished a chisel tonight and I'm satisfied with the results. May not be up to the standards of some of you guys but a marked improvement for myself. I flattened the back with sandpaper on granite, 220 - 320 - 400 - 800 - 1000 - 1500 (these are the grits I already had on hand), then onto 6000 and 8000 king waterstones. Still some very light, almost unnoticeable scratch marks, but I have a "mirror" finish in which I can see my reflection quite clearly with no distortion. I then used my honing guide (cheap one, forget where I even got it) to bevel at 25 degrees on my 1000 king waterstones, then honed at 30 degrees on 6000 and 8000. I then stropped the bevel and back. The chisel looks great with no visible imperfections in the edge or back and I'm paring white pine end grain with no effort at all. One thing I'm a little confused about...originally I worked the back with sandpaper, 220 - 320 - 400 - 800, which gave me a nice glimmery almost mirror sheen. I then moved to my 1000 king waterstone and that sheen was gone, turned very hazy with no "mirror" or reflectiveness (is that a word?). That's why I skipped the 1000 stone and kept with the sandpaper. Is this due to the abrasive grading difference between sandpaper (using p scale) and waterstones? Ultimately I don't care, I've found what works for me (for now).

[Patrick Chase]

Who knew?

I didn't.

Is there a central source for this oft-underappreciated information (i.e. discerning hardness/friability of stone w type of steel to be sharpened)?

You can get a lot of it from old SMC postings from when the "waterstone gang" were active (David Weaver, Chris Griggs, Stu from TfJ, etc). Stu also covered it a bit in his blog and various informational articles on TfJ. The Lee Valley waterstone information page (http://www.leevalley.com/us/HARDWARE/page.aspx?p=67175) (click "Guide to Full Size Waterstones) is pretty decent for a "quick start".

One thing that a lot of people miss is that the friability/speed tradeoffs are fundamentally very similar between grinding wheels and waterstones. The main difference is that the penalties for overly hard binder (and therefore worn-out abrasives) are worse when grinding. A waterstone with dulled abrasives at the cutting surface will just slow down, whereas a similarly degraded grinding wheel will dump heat into your tool and burn it.

[Brian Holcombe]

Wow! A lot of useful info here, some of which went way over my head. So thanks everyone. Took me a few days to get out into the shop but I finished a chisel tonight and I'm satisfied with the results. May not be up to the standards of some of you guys but a marked improvement for myself. I flattened the back with sandpaper on granite, 220 - 320 - 400 - 800 - 1000 - 1500 (these are the grits I already had on hand), then onto 6000 and 8000 king waterstones. Still some very light, almost unnoticeable scratch marks, but I have a "mirror" finish in which I can see my reflection quite clearly with no distortion. I then used my honing guide (cheap one, forget where I even got it) to bevel at 25 degrees on my 1000 king waterstones, then honed at 30 degrees on 6000 and 8000. I then stropped the bevel and back. The chisel looks great with no visible imperfections in the edge or back and I'm paring white pine end grain with no effort at all. One thing I'm a little confused about...originally I worked the back with sandpaper, 220 - 320 - 400 - 800, which gave me a nice glimmery almost mirror sheen. I then moved to my 1000 king waterstone and that sheen was gone, turned very hazy with no "mirror" or reflectiveness (is that a word?). That's why I skipped the 1000 stone and kept with the sandpaper. Is this due to the abrasive grading difference between sandpaper (using p scale) and waterstones? Ultimately I don't care, I've found what works for me (for now).

There is a trick to maintenance that is not immediately apparent that will make life easier moving forward now that the back is flat. When use the chisel it will be considered dull when there is a visible "wear bevel", accompanied by a difficulty in starting a cut. This wear presents as a bright line along the back at the edge. When you next work the bevel you must remove this wear bevel completely. Most often when someone wants to cheat the back (lift while sharpening the back) it is because the wear was not completely removed and so the burr is unable to be removed entirely and the chisel's edge will perform like a dull blade.

If you strop the back with compound you will find it difficult to maintain your blade, my suggestion is for you strop the back with a clean strop only.

[Robert Hazelwood]

I then moved to my 1000 king waterstone and that sheen was gone, turned very hazy with no "mirror" or reflectiveness (is that a word?). That's why I skipped the 1000 stone and kept with the sandpaper. Is this due to the abrasive grading difference between sandpaper (using p scale) and waterstones?

Partly. On the JIS scale that waterstones use, 1000 grit is indeed coarser than 1000 grit on the P scale. It is maybe in the 400-600 range, but it varies from stone to stone. But I think the haziness from the King is due to the scratch direction being more randomized than you get with sandpaper- this is due to the mud coming off the stone and creating loose abrasive slurry. On sandpaper the scratches are aligned, which seems to gives a more reflective surface for a given grit- even fairly coarse grits can give a reflection amidst the scratches.

Also, sandpaper particles, especially if Silicon Carbide, break down in use and become smaller and/or duller, which makes the paper effectively finer. Waterstones constantly release new grit so they cut at a more consistent rate.

But importantly, a mirror reflection is not an indication of sharpness. Most natural stones leave a hazy finish compared to a fine synthetic, but can produce extremely good edges.

[Jim Koepke]

Hi Dan, Robert explains this better than me. If you look at the back of a new Veritas blade it will look cloudy due to the randomness of the scratches. The scratches are at the micron level and the back is as perfectly flat as it can be, yet no mirror finish.

The large particles of coarse abrasives will burnish the edges of the scratch and look like a mirror even though there is quite a bit of roughness on the surface.

Scratches in coherent alignment may look mirror like. Incoherent out of alighment scratches on a sub micron level will have a cloudy look.

jtk

[David Ragan]

There is a trick to maintenance that is not immediately apparent that will make life easier moving forward now that the back is flat. When use the chisel it will be considered dull when there is a visible "wear bevel", accompanied by a difficulty in starting a cut. This wear presents as a bright line along the back at the edge. When you next work the bevel you must remove this wear bevel completely. Most often when someone wants to cheat the back (lift while sharpening the back) it is because the wear was not completely removed and so the burr is unable to be removed entirely and the chisel's edge will perform like a dull blade.

If you strop the back with compound you will find it difficult to maintain your blade, my suggestion is for you strop the back with a clean strop only.

Hi Brian,

I understand what you are saying-sort of.

Am familiar w wear bevel. It does seem like a lot of work to have to re-flatten the back of a chisel periodically. This is where the David Charlesworth ruler trick comes in?

Then, you say to strop the back w clean material (cloth/leather/wood,etc) only. I'm not getting the connection of why stropping w compound would make for more trouble.

Thanks, David

[Patrick Chase]

Partly. On the JIS scale that waterstones use, 1000 grit is indeed coarser than 1000 grit on the P scale.

This is completely backwards. 1000 on FEPA P-scale is 18 micron average particle size (http://www.imcclains.com/productinfo/documents/Grit%20Comparison%20Chart.pdf). Current "1000#" waterstones are between 10 and 15 um. IIRC the King is on the high side of that range.

EDIT: The King 1000# stone is 16 microns (http://www.leevalley.com/us/newsletters/Woodworking/5/4/article1-2.htm), so just a hair finer than FEPA P1000.

The current JIS-1998 spec calls out 11.5 um for a 1000# waterstone, so considerably finer than P1000. Similarly, the old JIS-1973 spec called out 15.5 um for 1000#, which is *still* finer than P1000.

Perhaps you've confused CAMI (which *is* finer than JIS at high grit #s) and FEPA P-scale here?



But I think the haziness from the King is due to the scratch direction being more randomized than you get with sandpaper- this is due to the mud coming off the stone and creating loose abrasive slurry. On sandpaper the scratches are aligned, which seems to gives a more reflective surface for a given grit- even fairly coarse grits can give a reflection amidst the scratches.
This part is right. The dull finish is caused by the presence of the loose grit (in slurry) on the surface of the waterstone. To achieve a mirror finish at such a low grit the scratches need to all be oriented the same way. That's true for sandpaper (assuming you lap in one direction), but the loose abrasive in a waterstone's slurry moves around fairly randomly, leading to a dull surface finish . This is also why Veritas tools come with very smooth but also very dull finishes - the lapping machine that they use moves the tool randomly over the abrasive.

As many people have said many time, a mirror finish tells you absolutely nothing whatsoever about surface smoothness or the quality of adjacent edges. The only thing you can infer from it is how the tool was sharpened. It's possible to get mirror finishes with unacceptably rough surfaces, and it's possible to get matte finishes with pristine ones (as with Veritas' fancy lapping machines).

IMO the "mirror finish myth" is one of the more harmful bits of disinformation that circulates amongst woodworkers.



Also, sandpaper particles, especially if Silicon Carbide, break down in use and become smaller and/or duller, which makes the paper effectively finer. Waterstones constantly release new grit so they cut at a more consistent rate.
There are two obvious problems with this argument. First, it depends on the hardness of the stone's binder. The King that the OP used is fairly hard, and tends to retain abrasive after it has started to break down and glaze. Second, the released abrasive sticks around in the form of a slurry (unless the user flushes it) and refines the cutting action a bit. There are some advanced waterstone techniques that exploit this to get the finest possible surface from polishing stones.

[Robert Hazelwood]

Well I stand corrected on the grit ratings. It could be that I have confused the scales...I was thinking of the typical black wet dry sandpaper which I don't believe is actually P scale? Not sure, really, and as you pointed out the loose abrasive is the dominant aspect here.

The 1000 King stone I had was super soft, and consistently created a heavy slurry without particular effort, resulting in a "bead blasted" finish. My impression is that this is pretty typical of Kings. In contrast my Shapton 1000 doesn't slurry much at all and leaves an aligned scratch pattern similar to sandpaper. I was assuming a soft binder in my comment.

[Robert Hazelwood]

Hi Brian,

I understand what you are saying-sort of.

Am familiar w wear bevel. It does seem like a lot of work to have to re-flatten the back of a chisel periodically. This is where the David Charlesworth ruler trick comes in?

Then, you say to strop the back w clean material (cloth/leather/wood,etc) only. I'm not getting the connection of why stropping w compound would make for more trouble.

Thanks, David

You wouldn't normally remove the wear bevel by re-flattening the back. The wear bevel is just a very shallow worn, rounded area at the tip on the back side. It will show up as a shiny line near the tip, and is usually more pronounced on plane irons than on chisels. You can remove it by working the bevel side sufficiently to move the edge back past the wear bevel. Often, this means you have to sharpen a bit past the point where you begin to feel a burr, which is where the standard sharpening advice tells you to stop. If you stop before completely removing the wear bevel, you can still get a fairly sharp edge, but it won't be the best edge and won't last as long. This is because there is still a tiny radius on the back at the edge, and so you can't actually get to the very edge when you are honing the back. So the burr cannot be totally removed even if it is too small to feel.

This is a tip I've picked up from reading Brian's posts and it has been extremely helpful.

I don't use it, but the ruler trick makes a lot of sense for dealing with the wear bevel on plane irons. It wouldn't be a good idea on most chisels though, since the flat back is so often used as a reference.

As for stropping, with a soft stop loaded with compound, even if you place the back flat on the strop the material will compress to some extent and kind of curl around the edge, putting a slight radius at the tip. Basically you would be stropping a wear bevel onto the back. You'd get a sharp edge, but the next sharpening will be more difficult because there will be an even larger wear bevel to remove. A bare leather strop removes the burr remnants without being abrasive enough to create any wear.

With a hardwood or mdf strop you can probably get away with using compound if you are careful.

[Brian Holcombe]

Thanks Robert, glad to hear that you have found that useful!

David,
Exactly as Robert says, I don't rework the back and what I'm driving at is a goal of not reworking the back ever. The only thing that happens with the back is that I will take a few strokes on the final finish stone to remove any hint of burr. The burr being untouched during this process will actually wear to a very very small amount on a good finish stone.
Using compound on a strop on the back of the blade makes this process more difficult, if not impossible, because it rounds the back ever so slightly. Doing so makes it so that the back won't contact the stone at the extreme edge.

So long as the wear pattern remains consistent on the back of my irons and chisels it tells me two things; one that they're flat to the degree that my final stone is capable of, and that my final stone is very flat. If you get an inconsistent pattern on the backs of your irons/chisels it means that either the back isn't flat, the stone isn't flat or both.

On western tools I use a plain strop to work the blade lightly before putting it back to work, on Japanese tools I won't do that.

[Paul Bent]

Thanks Robert, glad to hear that you have found that useful!



On western tools I use a plain strop to work the blade lightly before putting it back to work, on Japanese tools I won't do that.

Brian, what are your thoughts on why you do this?

[Brian Holcombe]

Why I strop one and not the other? Western tools have a big surface of hard steel, the smallest rounding and they won't clean off the burr on the finish stone. Japanese tools have a hollow, they can contact right up to the extreme edge.

[Patrick Chase]

Brian, what are your thoughts on why you do this?

The Japanese tools are harder and more brittle near the edge, and probably don't form wire edges to the same degree.

Now let's see if I got it right :-).

[Warren West]

waterstones are just about useless for flattening. The coarser they are the quicker they cut AND go out of flat. This is where diamond plates rule.

[Todd Stock]

Leveling takes the high spots down to the level of the low spot - it should not result in further removal of abrasive.

[Patrick Chase]

waterstones are just about useless for flattening. The coarser they are the quicker they cut AND go out of flat. This is where diamond plates rule.

I would reword this to "waterstones require good technique to be useful for flattening". You need to distribute the flattening workload across the stone (including all 4 edges) so that it wears down uniformly instead of developing hollows. Charlesworth covered one such technique in the FWW article that I linked earlier in this thread, though there are others.

You also need to know where waterstones do and don't make sense. I think that "one-shot" media (sandpaper, lapping film, compounds) are preferable below about 300#.

Also if you have a diamond plate then waterstone flattening is a triviality. Swiping the plate over your stone every so often adds maybe 5% to the total effort to flatten the back of a tool, of maybe a bit more if you don't distribute the flattening work across the stone.

I used diamond plates (DMT and Atoma) for flattening backs before I really figured out how to use waterstones, and while they are unquestionably more forgiving they have their own downsides. They tend to start out cutting very fast, but then they wear in and slow way down. If you replace them often enough to keep them cutting fast then the economics are absolutely awful, and if you don't then they lose all of their performance benefit.

FWIW my favorite flattening medium these days is diamond compound on steel or iron laps. In terms of performance it's basically equivalent to starting with a brand new diamond plate every time, but for a small fraction of the cost. The plates do have to be maintained (particularly if you allow the abrasive to rub off and form "bare spots", where the tool rubs against the plate itself) but as with waterstones that's a small fraction of the total effort.

If I were more cost-constrained then I'd go with waterstones.

[Pat Barry]

Patrick, you obviously know the ins and outs of sharpening. It would be nice to validate your sharpening expertise for us by showing some of the awesome projects you make with your super sharp and polished edges. Also, please learn how to not offend everyone with your approach to conveying your superior knowledge.

[Brian Holcombe]

Pat, with respect, I don't see anything offensive? Patrick's insights are quite helpful.

[Dave Zellers]

Agree. Been scratching my head over this.

[Pat Barry]

Pat, with respect, I don't see anything offensive? Patrick's insights are quite helpful.
I took issue with comment "mentally translate that to "the writer has no idea how to use waterstones"." I see no need to denigrate someone. Perhaps this statement wasn't necessary. I stand by my request for Patrick to show us some actual work as this would validate, to me at least, that he actually does know what he is talking about. Otherwise, I assume he is really just a google bot, regurgitating information that he has gleaned through research without actual practice.

[Jim Koepke]

I took issue with comment "mentally translate that to "the writer has no idea how to use waterstones"." I see no need to denigrate someone. Perhaps this statement wasn't necessary. I stand by my request for Patrick to show us some actual work as this would validate, to me at least, that he actually does know what he is talking about. Otherwise, I assume he is really just a google bot, regurgitating information that he has gleaned through research without actual practice.

A Google Bot?

Pat, are you suggesting Patrick actually may be a beta test of an AI program from a technology company? :eek:

There once was a way such charges were handled:

https://www.youtube.com/watch?v=zrzMhU_4m-g

jtk

[Dave Zellers]

Now I understand the push to get him to post videos.

To get a look at his nose!

[Dan McGonigle]

Hey guys, I've been "woodworking" for 5 or so years and I'm still very much a novice at best. As busy as my life is, those 5 years have been spent reading more about woodworking than actually making anything. I'm not ashamed at all to say that. I'm happily surprised how this post has received so much attention. Bottom line is I want to make sure my edge tools are as efficiently tuned as they can be (within reason) to provide the best possible results. I don't get much time in the shop so I want to make sure the time I do have is spent not fooling around with dull tools.

[Patrick Chase]

I took issue with comment "mentally translate that to "the writer has no idea how to use waterstones"." I see no need to denigrate someone. Perhaps this statement wasn't necessary.

You're right, I was out of line. That came more from frustration (because I felt that we'd already covered the need for technique when flattening on waterstones) than any hostile intent, but it wasn't helpful all the same. I've deleted that sentence.

[Patrick Chase]

A Google Bot?

Pat, are you suggesting Patrick actually may be a beta test of an AI program from a technology company? :eek:

There once was a way such charges were handled:

https://www.youtube.com/watch?v=zrzMhU_4m-g

jtk

I'm heavier than a duck.

[Patrick Chase]

Patrick, you obviously know the ins and outs of sharpening. It would be nice to validate your sharpening expertise for us by showing some of the awesome projects you make with your super sharp and polished edges. Also, please learn how to not offend everyone with your approach to conveying your superior knowledge.

I think I've been very blunt and honest from day 1 that I'm a far better engineer and (as you point out) tool maintainer than I am a woodworker. I pick and choose topics accordingly.